Installed new billet 42DD crack pipe and it leaks like a sive on the lower side is there suppose to be some sealeant im suppose to put around it?

Do a search this has happend b4 but I think it may have been wrong o ring size for one of the billet crack pipe manufacturers. One manufacturer was diff from the rest as far as o ring usuage....i think??

Did you clean the block where the crack pipe slides into the opening? Also use a tiny bit of engine assembly lube(comes in a tube) on the o-ring before sliding it into the block. You probably pinched the o-ring.

Take some sand paper to knock down any scaling on the block before installing the crack pipe. That'll also help you get a nice tight fit and stop the o-ring from getting pinched.